* [Qemu-devel] [PATCH v16 1/8] unblock backup operations in backing file
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 2/8] Backup: clear all bitmap when doing block checkpoint Changlong Xie
` (7 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
block.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/block.c b/block.c
index 0e165f9..c78cf47 100644
--- a/block.c
+++ b/block.c
@@ -1273,6 +1273,24 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
/* Otherwise we won't be able to commit due to check in bdrv_commit */
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
bs->backing_blocker);
+ /*
+ * We do backup in 3 ways:
+ * 1. drive backup
+ * The target bs is new opened, and the source is top BDS
+ * 2. blockdev backup
+ * Both the source and the target are top BDSes.
+ * 3. internal backup(used for block replication)
+ * Both the source and the target are backing file
+ *
+ * In case 1, and 2, the backing file is neither the source nor
+ * the target.
+ * In case 3, we will block the top BDS, so there is only one block
+ * job for the top BDS and its backing chain.
+ */
+ bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
+ bs->backing_blocker);
+ bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
+ bs->backing_blocker);
out:
bdrv_refresh_limits(bs, NULL);
}
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [Qemu-devel] [PATCH v16 2/8] Backup: clear all bitmap when doing block checkpoint
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 1/8] unblock backup operations in backing file Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-16 18:48 ` [Qemu-devel] [Qemu-block] " Jeff Cody
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 3/8] Link backup into block core Changlong Xie
` (6 subsequent siblings)
8 siblings, 1 reply; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
block/backup.c | 15 +++++++++++++++
include/block/block_int.h | 2 ++
2 files changed, 17 insertions(+)
diff --git a/block/backup.c b/block/backup.c
index 0f1b1bc..b2ba939 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -256,6 +256,21 @@ static void backup_abort(BlockJob *job)
}
}
+void backup_do_checkpoint(BlockJob *job, Error **errp)
+{
+ BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
+
+ assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
+
+ if (backup_job->sync_mode != MIRROR_SYNC_MODE_NONE) {
+ error_setg(errp, "The backup job only supports block checkpoint in"
+ " sync=none mode");
+ return;
+ }
+
+ hbitmap_reset_all(backup_job->bitmap);
+}
+
static const BlockJobDriver backup_job_driver = {
.instance_size = sizeof(BackupBlockJob),
.job_type = BLOCK_JOB_TYPE_BACKUP,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 704efe5..48f0f1f 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -699,6 +699,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
BlockCompletionFunc *cb, void *opaque,
BlockJobTxn *txn, Error **errp);
+void backup_do_checkpoint(BlockJob *job, Error **errp);
+
void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
void blk_dev_change_media_cb(BlockBackend *blk, bool load);
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [Qemu-devel] [Qemu-block] [PATCH v16 2/8] Backup: clear all bitmap when doing block checkpoint
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 2/8] Backup: clear all bitmap when doing block checkpoint Changlong Xie
@ 2016-03-16 18:48 ` Jeff Cody
2016-03-17 1:22 ` Changlong Xie
0 siblings, 1 reply; 13+ messages in thread
From: Jeff Cody @ 2016-03-16 18:48 UTC (permalink / raw)
To: Changlong Xie
Cc: Kevin Wolf, Fam Zheng, qemu block, Jiang Yunhong, Dong Eddie,
qemu devel, Michael R. Hines, Max Reitz, Gonglei, Stefan Hajnoczi,
Paolo Bonzini, Dr. David Alan Gilbert, zhanghailiang
On Fri, Mar 11, 2016 at 06:34:09PM +0800, Changlong Xie wrote:
> From: Wen Congyang <wency@cn.fujitsu.com>
>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
> ---
> block/backup.c | 15 +++++++++++++++
> include/block/block_int.h | 2 ++
> 2 files changed, 17 insertions(+)
>
> diff --git a/block/backup.c b/block/backup.c
> index 0f1b1bc..b2ba939 100644
> --- a/block/backup.c
> +++ b/block/backup.c
> @@ -256,6 +256,21 @@ static void backup_abort(BlockJob *job)
> }
> }
>
> +void backup_do_checkpoint(BlockJob *job, Error **errp)
> +{
> + BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
> +
> + assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
> +
> + if (backup_job->sync_mode != MIRROR_SYNC_MODE_NONE) {
> + error_setg(errp, "The backup job only supports block checkpoint in"
> + " sync=none mode");
> + return;
> + }
> +
> + hbitmap_reset_all(backup_job->bitmap);
This variable changed name and type, it is a simple bitmap now called
'done_bitmap' (backup_job->done_bitmap), and type 'unsigned long *'.
> +}
> +
> static const BlockJobDriver backup_job_driver = {
> .instance_size = sizeof(BackupBlockJob),
> .job_type = BLOCK_JOB_TYPE_BACKUP,
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index 704efe5..48f0f1f 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -699,6 +699,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
> BlockCompletionFunc *cb, void *opaque,
> BlockJobTxn *txn, Error **errp);
>
> +void backup_do_checkpoint(BlockJob *job, Error **errp);
> +
> void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
>
> void blk_dev_change_media_cb(BlockBackend *blk, bool load);
> --
> 1.9.3
>
>
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [Qemu-devel] [Qemu-block] [PATCH v16 2/8] Backup: clear all bitmap when doing block checkpoint
2016-03-16 18:48 ` [Qemu-devel] [Qemu-block] " Jeff Cody
@ 2016-03-17 1:22 ` Changlong Xie
0 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-17 1:22 UTC (permalink / raw)
To: Jeff Cody
Cc: Kevin Wolf, Fam Zheng, qemu block, Jiang Yunhong, Dong Eddie,
qemu devel, Michael R. Hines, Max Reitz, Gonglei, Stefan Hajnoczi,
Paolo Bonzini, Dr. David Alan Gilbert, zhanghailiang
On 03/17/2016 02:48 AM, Jeff Cody wrote:
> On Fri, Mar 11, 2016 at 06:34:09PM +0800, Changlong Xie wrote:
>> From: Wen Congyang <wency@cn.fujitsu.com>
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
>> ---
>> block/backup.c | 15 +++++++++++++++
>> include/block/block_int.h | 2 ++
>> 2 files changed, 17 insertions(+)
>>
>> diff --git a/block/backup.c b/block/backup.c
>> index 0f1b1bc..b2ba939 100644
>> --- a/block/backup.c
>> +++ b/block/backup.c
>> @@ -256,6 +256,21 @@ static void backup_abort(BlockJob *job)
>> }
>> }
>>
>> +void backup_do_checkpoint(BlockJob *job, Error **errp)
>> +{
>> + BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
>> +
>> + assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
>> +
>> + if (backup_job->sync_mode != MIRROR_SYNC_MODE_NONE) {
>> + error_setg(errp, "The backup job only supports block checkpoint in"
>> + " sync=none mode");
>> + return;
>> + }
>> +
>> + hbitmap_reset_all(backup_job->bitmap);
>
> This variable changed name and type, it is a simple bitmap now called
> 'done_bitmap' (backup_job->done_bitmap), and type 'unsigned long *'.
Thanks for pointing it out, will fix in next version.
Thanks
-Xie
>
>> +}
>> +
>> static const BlockJobDriver backup_job_driver = {
>> .instance_size = sizeof(BackupBlockJob),
>> .job_type = BLOCK_JOB_TYPE_BACKUP,
>> diff --git a/include/block/block_int.h b/include/block/block_int.h
>> index 704efe5..48f0f1f 100644
>> --- a/include/block/block_int.h
>> +++ b/include/block/block_int.h
>> @@ -699,6 +699,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
>> BlockCompletionFunc *cb, void *opaque,
>> BlockJobTxn *txn, Error **errp);
>>
>> +void backup_do_checkpoint(BlockJob *job, Error **errp);
>> +
>> void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
>>
>> void blk_dev_change_media_cb(BlockBackend *blk, bool load);
>> --
>> 1.9.3
>>
>>
>>
>>
>
>
> .
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] [PATCH v16 3/8] Link backup into block core
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 1/8] unblock backup operations in backing file Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 2/8] Backup: clear all bitmap when doing block checkpoint Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 4/8] docs: block replication's description Changlong Xie
` (5 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Some programs that add a dependency on it will use
the block layer directly.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
---
block/Makefile.objs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 58ef2ef..fa05f37 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -22,10 +22,10 @@ block-obj-$(CONFIG_ARCHIPELAGO) += archipelago.o
block-obj-$(CONFIG_LIBSSH2) += ssh.o
block-obj-y += accounting.o
block-obj-y += write-threshold.o
+block-obj-y += backup.o
common-obj-y += stream.o
common-obj-y += commit.o
-common-obj-y += backup.o
iscsi.o-cflags := $(LIBISCSI_CFLAGS)
iscsi.o-libs := $(LIBISCSI_LIBS)
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [Qemu-devel] [PATCH v16 4/8] docs: block replication's description
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
` (2 preceding siblings ...)
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 3/8] Link backup into block core Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-28 6:14 ` Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 5/8] auto complete active commit Changlong Xie
` (4 subsequent siblings)
8 siblings, 1 reply; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
docs/block-replication.txt | 238 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 238 insertions(+)
create mode 100644 docs/block-replication.txt
diff --git a/docs/block-replication.txt b/docs/block-replication.txt
new file mode 100644
index 0000000..b696491
--- /dev/null
+++ b/docs/block-replication.txt
@@ -0,0 +1,238 @@
+Block replication
+----------------------------------------
+Copyright Fujitsu, Corp. 2016
+Copyright (c) 2016 Intel Corporation
+Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+
+This work is licensed under the terms of the GNU GPL, version 2 or later.
+See the COPYING file in the top-level directory.
+
+Block replication is used for continuous checkpoints. It is designed
+for COLO (COarse-grain LOck-stepping) where the Secondary VM is running.
+It can also be applied for FT/HA (Fault-tolerance/High Assurance) scenario,
+where the Secondary VM is not running.
+
+This document gives an overview of block replication's design.
+
+== Background ==
+High availability solutions such as micro checkpoint and COLO will do
+consecutive checkpoints. The VM state of the Primary and Secondary VM is
+identical right after a VM checkpoint, but becomes different as the VM
+executes till the next checkpoint. To support disk contents checkpoint,
+the modified disk contents in the Secondary VM must be buffered, and are
+only dropped at next checkpoint time. To reduce the network transportation
+effort during a vmstate checkpoint, the disk modification operations of
+the Primary disk are asynchronously forwarded to the Secondary node.
+
+== Workflow ==
+The following is the image of block replication workflow:
+
+ +----------------------+ +------------------------+
+ |Primary Write Requests| |Secondary Write Requests|
+ +----------------------+ +------------------------+
+ | |
+ | (4)
+ | V
+ | /-------------\
+ | Copy and Forward | |
+ |---------(1)----------+ | Disk Buffer |
+ | | | |
+ | (3) \-------------/
+ | speculative ^
+ | write through (2)
+ | | |
+ V V |
+ +--------------+ +----------------+
+ | Primary Disk | | Secondary Disk |
+ +--------------+ +----------------+
+
+ 1) Primary write requests will be copied and forwarded to Secondary
+ QEMU.
+ 2) Before Primary write requests are written to Secondary disk, the
+ original sector content will be read from Secondary disk and
+ buffered in the Disk buffer, but it will not overwrite the existing
+ sector content (it could be from either "Secondary Write Requests" or
+ previous COW of "Primary Write Requests") in the Disk buffer.
+ 3) Primary write requests will be written to Secondary disk.
+ 4) Secondary write requests will be buffered in the Disk buffer and it
+ will overwrite the existing sector content in the buffer.
+
+== Architecture ==
+We are going to implement block replication from many basic
+blocks that are already in QEMU.
+
+ virtio-blk ||
+ ^ || .----------
+ | || | Secondary
+ 1 Quorum || '----------
+ / \ ||
+ / \ ||
+ Primary 2 filter
+ disk ^ virtio-blk
+ | ^
+ 3 NBD -------> 3 NBD |
+ client || server 2 filter
+ || ^ ^
+--------. || | |
+Primary | || Secondary disk <--------- hidden-disk 5 <--------- active-disk 4
+--------' || | backing ^ backing
+ || | |
+ || | |
+ || '-------------------------'
+ || drive-backup sync=none 6
+
+1) The disk on the primary is represented by a block device with two
+children, providing replication between a primary disk and the host that
+runs the secondary VM. The read pattern for quorum can be extended to
+make the primary always read from the local disk instead of going through
+NBD.
+
+2) The new block filter (the name is replication) will control the block
+replication.
+
+3) The secondary disk receives writes from the primary VM through QEMU's
+embedded NBD server (speculative write-through).
+
+4) The disk on the secondary is represented by a custom block device
+(called active-disk). It should start as an empty disk, and the format
+should support bdrv_make_empty() and backing file.
+
+5) The hidden-disk is created automatically. It buffers the original content
+that is modified by the primary VM. It should also start as an empty disk,
+and the driver supports bdrv_make_empty() and backing file.
+
+6) The drive-backup job (sync=none) is run to allow hidden-disk to buffer
+any state that would otherwise be lost by the speculative write-through
+of the NBD server into the secondary disk. So before block replication,
+the primary disk and secondary disk should contain the same data.
+
+== Failure Handling ==
+There are 7 internal errors when block replication is running:
+1. I/O error on primary disk
+2. Forwarding primary write requests failed
+3. Backup failed
+4. I/O error on secondary disk
+5. I/O error on active disk
+6. Making active disk or hidden disk empty failed
+7. Doing failover failed
+In case 1 and 5, we just report the error to the disk layer. In case 2, 3,
+4 and 6, we just report block replication's error to FT/HA manager (which
+decides when to do a new checkpoint, when to do failover).
+In case 7, if active commit failed, we use replication failover failed state
+in Secondary's write operation (what decides which target to write).
+
+== New block driver interface ==
+We add three block driver interfaces to control block replication:
+a. replication_start_all()
+ Start block replication, called in migration/checkpoint thread.
+ We must call block_replication_start_all() in secondary QEMU before
+ calling block_replication_start_all() in primary QEMU. The caller
+ must hold the I/O mutex lock if it is in migration/checkpoint
+ thread.
+b. replication_do_checkpoint_all()
+ This interface is called after all VM state is transferred to
+ Secondary QEMU. The Disk buffer will be dropped in this interface.
+ The caller must hold the I/O mutex lock if it is in migration/checkpoint
+ thread.
+c. replication_get_error_all()
+ This interface is called to check if error happened in replication.
+ The caller must hold the I/O mutex lock if it is in migration/checkpoint
+ thread.
+d. replication_stop_all()
+ It is called on failover. We will flush the Disk buffer into
+ Secondary Disk and stop block replication. The vm should be stopped
+ before calling it if you use this API to shutdown the guest, or other
+ things except failover. The caller must hold the I/O mutex lock if it is
+ in migration/checkpoint thread.
+
+== Usage ==
+Primary:
+ -drive if=xxx,driver=quorum,read-pattern=fifo,id=colo1,vote-threshold=1,\
+ children.0.file.filename=1.raw,\
+ children.0.driver=raw
+
+ Run qmp command in primary qemu:
+ { 'execute': 'human-monitor-command',
+ 'arguments': {
+ 'command-line': 'drive_add buddy driver=replication,mode=primary,file.driver=nbd,file.host=xxxx,file.port=xxxx,file.export=colo1,node-name=nbd_client1,if=none,id=xxxx'
+ }
+ }
+ { 'execute': 'x-blockdev-change',
+ 'arguments': {
+ 'parent': 'colo1',
+ 'node': 'nbd_client1'
+ }
+ }
+ Note:
+ 1. There should be only one NBD Client for each primary disk.
+ 2. host is the secondary physical machine's hostname or IP
+ 3. Each disk must have its own export name.
+ 4. It is all a single argument to -drive and you should ignore the
+ leading whitespace.
+ 5. The qmp command line must be run after running qmp command line in
+ secondary qemu.
+
+Secondary:
+ -drive if=none,driver=raw,file.filename=1.raw,id=colo1 \
+ -drive if=xxx,id=topxxx,driver=replication,mode=secondary,top-id=topxxx\
+ file.file.filename=active_disk.qcow2,\
+ file.driver=qcow2,\
+ file.backing.file.filename=hidden_disk.qcow2,\
+ file.backing.driver=qcow2,\
+ file.backing.backing=colo1
+
+ Then run qmp command in secondary qemu:
+ { 'execute': 'nbd-server-start',
+ 'arguments': {
+ 'addr': {
+ 'type': 'inet',
+ 'data': {
+ 'host': 'xxx',
+ 'port': 'xxx'
+ }
+ }
+ }
+ }
+ { 'execute': 'nbd-server-add',
+ 'arguments': {
+ 'device': 'colo1',
+ 'writable': true
+ }
+ }
+
+ Note:
+ 1. The export name in secondary QEMU command line is the secondary
+ disk's id.
+ 2. The export name for the same disk must be the same
+ 3. The qmp command nbd-server-start and nbd-server-add must be run
+ before running the qmp command migrate on primary QEMU
+ 4. Active disk, hidden disk and nbd target's length should be the
+ same.
+ 5. It is better to put active disk and hidden disk in ramdisk.
+ 6. It is all a single argument to -drive, and you should ignore
+ the leading whitespace.
+
+After Failover:
+Primary:
+ The secondary host is down, so we should run the following qmp command
+ to remove the nbd child from the quorum:
+ { 'execute': 'x-blockdev-change',
+ 'arguments': {
+ 'parent': 'colo1',
+ 'child': 'children.1'
+ }
+ }
+ { 'execute': 'human-monitor-command',
+ 'arguments': {
+ 'command-line': 'drive_del xxxx'
+ }
+ }
+ Note: there is no qmp command to remove the blockdev now
+
+Secondary:
+ The primary host is down, so we should do the following thing:
+ { 'execute': 'nbd-server-stop' }
+
+TODO:
+1. Continuous block replication
+2. Shared disk
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [Qemu-devel] [PATCH v16 4/8] docs: block replication's description
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 4/8] docs: block replication's description Changlong Xie
@ 2016-03-28 6:14 ` Changlong Xie
0 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-28 6:14 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: qemu block, Jiang Yunhong, Dong Eddie, Dr. David Alan Gilbert,
Michael R. Hines, Gonglei, zhanghailiang
On 03/11/2016 06:34 PM, Changlong Xie wrote:
> From: Wen Congyang <wency@cn.fujitsu.com>
>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
> ---
> docs/block-replication.txt | 238 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 238 insertions(+)
> create mode 100644 docs/block-replication.txt
>
> diff --git a/docs/block-replication.txt b/docs/block-replication.txt
> new file mode 100644
> index 0000000..b696491
> --- /dev/null
> +++ b/docs/block-replication.txt
> @@ -0,0 +1,238 @@
> +Block replication
> +----------------------------------------
> +Copyright Fujitsu, Corp. 2016
> +Copyright (c) 2016 Intel Corporation
> +Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
> +
> +This work is licensed under the terms of the GNU GPL, version 2 or later.
> +See the COPYING file in the top-level directory.
> +
> +Block replication is used for continuous checkpoints. It is designed
> +for COLO (COarse-grain LOck-stepping) where the Secondary VM is running.
> +It can also be applied for FT/HA (Fault-tolerance/High Assurance) scenario,
> +where the Secondary VM is not running.
> +
> +This document gives an overview of block replication's design.
> +
> +== Background ==
> +High availability solutions such as micro checkpoint and COLO will do
> +consecutive checkpoints. The VM state of the Primary and Secondary VM is
> +identical right after a VM checkpoint, but becomes different as the VM
> +executes till the next checkpoint. To support disk contents checkpoint,
> +the modified disk contents in the Secondary VM must be buffered, and are
> +only dropped at next checkpoint time. To reduce the network transportation
> +effort during a vmstate checkpoint, the disk modification operations of
> +the Primary disk are asynchronously forwarded to the Secondary node.
> +
> +== Workflow ==
> +The following is the image of block replication workflow:
> +
> + +----------------------+ +------------------------+
> + |Primary Write Requests| |Secondary Write Requests|
> + +----------------------+ +------------------------+
> + | |
> + | (4)
> + | V
> + | /-------------\
> + | Copy and Forward | |
> + |---------(1)----------+ | Disk Buffer |
> + | | | |
> + | (3) \-------------/
> + | speculative ^
> + | write through (2)
> + | | |
> + V V |
> + +--------------+ +----------------+
> + | Primary Disk | | Secondary Disk |
> + +--------------+ +----------------+
> +
> + 1) Primary write requests will be copied and forwarded to Secondary
> + QEMU.
> + 2) Before Primary write requests are written to Secondary disk, the
> + original sector content will be read from Secondary disk and
> + buffered in the Disk buffer, but it will not overwrite the existing
> + sector content (it could be from either "Secondary Write Requests" or
> + previous COW of "Primary Write Requests") in the Disk buffer.
> + 3) Primary write requests will be written to Secondary disk.
> + 4) Secondary write requests will be buffered in the Disk buffer and it
> + will overwrite the existing sector content in the buffer.
> +
> +== Architecture ==
> +We are going to implement block replication from many basic
> +blocks that are already in QEMU.
> +
> + virtio-blk ||
> + ^ || .----------
> + | || | Secondary
> + 1 Quorum || '----------
> + / \ ||
> + / \ ||
> + Primary 2 filter
> + disk ^ virtio-blk
> + | ^
> + 3 NBD -------> 3 NBD |
> + client || server 2 filter
> + || ^ ^
> +--------. || | |
> +Primary | || Secondary disk <--------- hidden-disk 5 <--------- active-disk 4
> +--------' || | backing ^ backing
> + || | |
> + || | |
> + || '-------------------------'
> + || drive-backup sync=none 6
> +
> +1) The disk on the primary is represented by a block device with two
> +children, providing replication between a primary disk and the host that
> +runs the secondary VM. The read pattern for quorum can be extended to
> +make the primary always read from the local disk instead of going through
> +NBD.
> +
> +2) The new block filter (the name is replication) will control the block
> +replication.
> +
> +3) The secondary disk receives writes from the primary VM through QEMU's
> +embedded NBD server (speculative write-through).
> +
> +4) The disk on the secondary is represented by a custom block device
> +(called active-disk). It should start as an empty disk, and the format
> +should support bdrv_make_empty() and backing file.
> +
> +5) The hidden-disk is created automatically. It buffers the original content
> +that is modified by the primary VM. It should also start as an empty disk,
> +and the driver supports bdrv_make_empty() and backing file.
> +
> +6) The drive-backup job (sync=none) is run to allow hidden-disk to buffer
> +any state that would otherwise be lost by the speculative write-through
> +of the NBD server into the secondary disk. So before block replication,
> +the primary disk and secondary disk should contain the same data.
> +
> +== Failure Handling ==
> +There are 7 internal errors when block replication is running:
> +1. I/O error on primary disk
> +2. Forwarding primary write requests failed
> +3. Backup failed
> +4. I/O error on secondary disk
> +5. I/O error on active disk
> +6. Making active disk or hidden disk empty failed
> +7. Doing failover failed
> +In case 1 and 5, we just report the error to the disk layer. In case 2, 3,
> +4 and 6, we just report block replication's error to FT/HA manager (which
> +decides when to do a new checkpoint, when to do failover).
> +In case 7, if active commit failed, we use replication failover failed state
> +in Secondary's write operation (what decides which target to write).
> +
> +== New block driver interface ==
> +We add three block driver interfaces to control block replication:
> +a. replication_start_all()
> + Start block replication, called in migration/checkpoint thread.
> + We must call block_replication_start_all() in secondary QEMU before
> + calling block_replication_start_all() in primary QEMU. The caller
> + must hold the I/O mutex lock if it is in migration/checkpoint
> + thread.
> +b. replication_do_checkpoint_all()
> + This interface is called after all VM state is transferred to
> + Secondary QEMU. The Disk buffer will be dropped in this interface.
> + The caller must hold the I/O mutex lock if it is in migration/checkpoint
> + thread.
> +c. replication_get_error_all()
> + This interface is called to check if error happened in replication.
> + The caller must hold the I/O mutex lock if it is in migration/checkpoint
> + thread.
> +d. replication_stop_all()
> + It is called on failover. We will flush the Disk buffer into
> + Secondary Disk and stop block replication. The vm should be stopped
> + before calling it if you use this API to shutdown the guest, or other
> + things except failover. The caller must hold the I/O mutex lock if it is
> + in migration/checkpoint thread.
> +
> +== Usage ==
> +Primary:
> + -drive if=xxx,driver=quorum,read-pattern=fifo,id=colo1,vote-threshold=1,\
> + children.0.file.filename=1.raw,\
> + children.0.driver=raw
> +
> + Run qmp command in primary qemu:
> + { 'execute': 'human-monitor-command',
> + 'arguments': {
> + 'command-line': 'drive_add buddy driver=replication,mode=primary,file.driver=nbd,file.host=xxxx,file.port=xxxx,file.export=colo1,node-name=nbd_client1,if=none,id=xxxx'
Commit abb21ac3 introduce '-n' for 'drive_add' to create a node without
BB, so we Must not pass "if=node,id=xxx' to it. Will fix in next version
Thanks
-Xie
> + }
> + }
> + { 'execute': 'x-blockdev-change',
> + 'arguments': {
> + 'parent': 'colo1',
> + 'node': 'nbd_client1'
> + }
> + }
> + Note:
> + 1. There should be only one NBD Client for each primary disk.
> + 2. host is the secondary physical machine's hostname or IP
> + 3. Each disk must have its own export name.
> + 4. It is all a single argument to -drive and you should ignore the
> + leading whitespace.
> + 5. The qmp command line must be run after running qmp command line in
> + secondary qemu.
> +
> +Secondary:
> + -drive if=none,driver=raw,file.filename=1.raw,id=colo1 \
> + -drive if=xxx,id=topxxx,driver=replication,mode=secondary,top-id=topxxx\
> + file.file.filename=active_disk.qcow2,\
> + file.driver=qcow2,\
> + file.backing.file.filename=hidden_disk.qcow2,\
> + file.backing.driver=qcow2,\
> + file.backing.backing=colo1
> +
> + Then run qmp command in secondary qemu:
> + { 'execute': 'nbd-server-start',
> + 'arguments': {
> + 'addr': {
> + 'type': 'inet',
> + 'data': {
> + 'host': 'xxx',
> + 'port': 'xxx'
> + }
> + }
> + }
> + }
> + { 'execute': 'nbd-server-add',
> + 'arguments': {
> + 'device': 'colo1',
> + 'writable': true
> + }
> + }
> +
> + Note:
> + 1. The export name in secondary QEMU command line is the secondary
> + disk's id.
> + 2. The export name for the same disk must be the same
> + 3. The qmp command nbd-server-start and nbd-server-add must be run
> + before running the qmp command migrate on primary QEMU
> + 4. Active disk, hidden disk and nbd target's length should be the
> + same.
> + 5. It is better to put active disk and hidden disk in ramdisk.
> + 6. It is all a single argument to -drive, and you should ignore
> + the leading whitespace.
> +
> +After Failover:
> +Primary:
> + The secondary host is down, so we should run the following qmp command
> + to remove the nbd child from the quorum:
> + { 'execute': 'x-blockdev-change',
> + 'arguments': {
> + 'parent': 'colo1',
> + 'child': 'children.1'
> + }
> + }
> + { 'execute': 'human-monitor-command',
> + 'arguments': {
> + 'command-line': 'drive_del xxxx'
> + }
> + }
> + Note: there is no qmp command to remove the blockdev now
> +
> +Secondary:
> + The primary host is down, so we should do the following thing:
> + { 'execute': 'nbd-server-stop' }
> +
> +TODO:
> +1. Continuous block replication
> +2. Shared disk
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] [PATCH v16 5/8] auto complete active commit
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
` (3 preceding siblings ...)
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 4/8] docs: block replication's description Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 6/8] Introduce new APIs to do replication operation Changlong Xie
` (3 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Auto complete mirror job in background to prevent from
blocking synchronously
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
block/mirror.c | 13 +++++++++----
blockdev.c | 2 +-
include/block/block_int.h | 3 ++-
qemu-img.c | 2 +-
4 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 9635fa8..9962882 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -789,7 +789,8 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
BlockCompletionFunc *cb,
void *opaque, Error **errp,
const BlockJobDriver *driver,
- bool is_none_mode, BlockDriverState *base)
+ bool is_none_mode, BlockDriverState *base,
+ bool auto_complete)
{
MirrorBlockJob *s;
BlockDriverState *replaced_bs;
@@ -845,6 +846,9 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
s->granularity = granularity;
s->buf_size = ROUND_UP(buf_size, granularity);
s->unmap = unmap;
+ if (auto_complete) {
+ s->should_complete = true;
+ }
s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
if (!s->dirty_bitmap) {
@@ -886,14 +890,15 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target,
mirror_start_job(bs, target, replaces,
speed, granularity, buf_size,
on_source_error, on_target_error, unmap, cb, opaque, errp,
- &mirror_job_driver, is_none_mode, base);
+ &mirror_job_driver, is_none_mode, base, false);
}
void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
int64_t speed,
BlockdevOnError on_error,
BlockCompletionFunc *cb,
- void *opaque, Error **errp)
+ void *opaque, Error **errp,
+ bool auto_complete)
{
int64_t length, base_length;
int orig_base_flags;
@@ -934,7 +939,7 @@ void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
bdrv_ref(base);
mirror_start_job(bs, base, NULL, speed, 0, 0,
on_error, on_error, false, cb, opaque, &local_err,
- &commit_active_job_driver, false, base);
+ &commit_active_job_driver, false, base, auto_complete);
if (local_err) {
error_propagate(errp, local_err);
goto error_restore_flags;
diff --git a/blockdev.c b/blockdev.c
index 435631e..02ca28c 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3114,7 +3114,7 @@ void qmp_block_commit(const char *device,
goto out;
}
commit_active_start(bs, base_bs, speed, on_error, block_job_cb,
- bs, &local_err);
+ bs, &local_err, false);
} else {
commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,
has_backing_file ? backing_file : NULL, &local_err);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 48f0f1f..450aec7 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -637,13 +637,14 @@ void commit_start(BlockDriverState *bs, BlockDriverState *base,
* @cb: Completion function for the job.
* @opaque: Opaque pointer value passed to @cb.
* @errp: Error object.
+ * @auto_complete: Auto complete the job.
*
*/
void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
int64_t speed,
BlockdevOnError on_error,
BlockCompletionFunc *cb,
- void *opaque, Error **errp);
+ void *opaque, Error **errp, bool auto_complete);
/*
* mirror_start:
* @bs: Block device to operate on.
diff --git a/qemu-img.c b/qemu-img.c
index 2edb139..878a50a 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -910,7 +910,7 @@ static int img_commit(int argc, char **argv)
};
commit_active_start(bs, base_bs, 0, BLOCKDEV_ON_ERROR_REPORT,
- common_block_job_cb, &cbi, &local_err);
+ common_block_job_cb, &cbi, &local_err, false);
if (local_err) {
goto done;
}
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [Qemu-devel] [PATCH v16 6/8] Introduce new APIs to do replication operation
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
` (4 preceding siblings ...)
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 5/8] auto complete active commit Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 7/8] Implement new driver for block replication Changlong Xie
` (2 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
Makefile.objs | 1 +
qapi/block-core.json | 13 ++++
replication.c | 94 +++++++++++++++++++++++++++
replication.h | 175 +++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 283 insertions(+)
create mode 100644 replication.c
create mode 100644 replication.h
diff --git a/Makefile.objs b/Makefile.objs
index fbcaa74..6df7b37 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -15,6 +15,7 @@ block-obj-$(CONFIG_POSIX) += aio-posix.o
block-obj-$(CONFIG_WIN32) += aio-win32.o
block-obj-y += block/
block-obj-y += qemu-io-cmds.o
+block-obj-y += replication.o
block-obj-m = block/
diff --git a/qapi/block-core.json b/qapi/block-core.json
index bc3fd0b..c580a0f 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2068,6 +2068,19 @@
'*read-pattern': 'QuorumReadPattern' } }
##
+# @ReplicationMode
+#
+# An enumeration of replication modes.
+#
+# @primary: Primary mode, the vm's state will be sent to secondary QEMU.
+#
+# @secondary: Secondary mode, receive the vm's state from primary QEMU.
+#
+# Since: 2.6
+##
+{ 'enum' : 'ReplicationMode', 'data' : [ 'primary', 'secondary' ] }
+
+##
# @BlockdevOptions
#
# Options for creating a block device.
diff --git a/replication.c b/replication.c
new file mode 100644
index 0000000..0b8b96d
--- /dev/null
+++ b/replication.c
@@ -0,0 +1,94 @@
+/*
+ * Replication filter
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2016 FUJITSU LIMITED
+ *
+ * Author:
+ * Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "replication.h"
+
+static QLIST_HEAD(, ReplicationState) replication_states;
+
+ReplicationState *replication_new(void *opaque, ReplicationOps *ops)
+{
+ ReplicationState *rs;
+
+ rs = g_new0(ReplicationState, 1);
+ rs->opaque = opaque;
+ rs->ops = ops;
+ QLIST_INSERT_HEAD(&replication_states, rs, node);
+
+ return rs;
+}
+
+void replication_remove(ReplicationState *rs)
+{
+ QLIST_REMOVE(rs, node);
+ g_free(rs);
+}
+
+/*
+ * The caller of the function *MUST* make sure vm stopped
+ */
+void replication_start_all(ReplicationMode mode, Error **errp)
+{
+ ReplicationState *rs, *next;
+
+ QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
+ if (rs->ops && rs->ops->start) {
+ rs->ops->start(rs, mode, errp);
+ }
+ if (errp && *errp) {
+ return;
+ }
+ }
+}
+
+void replication_do_checkpoint_all(Error **errp)
+{
+ ReplicationState *rs, *next;
+
+ QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
+ if (rs->ops && rs->ops->checkpoint) {
+ rs->ops->checkpoint(rs, errp);
+ }
+ if (errp && *errp) {
+ return;
+ }
+ }
+}
+
+void replication_get_error_all(Error **errp)
+{
+ ReplicationState *rs, *next;
+
+ QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
+ if (rs->ops && rs->ops->get_error) {
+ rs->ops->get_error(rs, errp);
+ }
+ if (errp && *errp) {
+ return;
+ }
+ }
+}
+
+void replication_stop_all(bool failover, Error **errp)
+{
+ ReplicationState *rs, *next;
+
+ QLIST_FOREACH_SAFE(rs, &replication_states, node, next) {
+ if (rs->ops && rs->ops->stop) {
+ rs->ops->stop(rs, failover, errp);
+ }
+ if (errp && *errp) {
+ return;
+ }
+ }
+}
diff --git a/replication.h b/replication.h
new file mode 100644
index 0000000..b3a2b28
--- /dev/null
+++ b/replication.h
@@ -0,0 +1,175 @@
+/*
+ * Replication filter
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2016 FUJITSU LIMITED
+ *
+ * Author:
+ * Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef REPLICATION_H
+#define REPLICATION_H
+
+#include "qemu/osdep.h"
+#include "sysemu/sysemu.h"
+
+typedef struct ReplicationOps ReplicationOps;
+typedef struct ReplicationState ReplicationState;
+
+/**
+ * SECTION:replication.h
+ * @title:Base Replication System
+ * @short_description: interfaces for handle replication
+ *
+ * The Replication Model provides a framework for handle Replication
+ *
+ * <example>
+ * <title>How to use replication interface</title>
+ * <programlisting>
+ * #include "replication.h"
+ *
+ * typedef struct BDRVReplicationState {
+ * ReplicationState *rs;
+ * } BDRVReplicationState;
+ *
+ * static void replication_start(ReplicationState *rs, ReplicationMode mode,
+ * Error **errp);
+ * static void replication_do_checkpoint(ReplicationState *rs, Error **errp);
+ * static void replication_get_error(ReplicationState *rs, Error **errp);
+ * static void replication_stop(ReplicationState *rs, bool failover,
+ * Error **errp);
+ *
+ * static ReplicationOps replication_ops = {
+ * .start = replication_start,
+ * .checkpoint = replication_do_checkpoint,
+ * .get_error = replication_get_error,
+ * .stop = replication_stop,
+ * }
+ *
+ * static int replication_open(BlockDriverState *bs, QDict *options,
+ * int flags, Error **errp)
+ * {
+ * BDRVReplicationState *s = bs->opaque;
+ * s->rs = replication_new(bs, &replication_ops);
+ * return 0;
+ * }
+ *
+ * static void replication_close(BlockDriverState *bs)
+ * {
+ * BDRVReplicationState *s = bs->opaque;
+ * replication_remove(s->rs);
+ * }
+ *
+ * BlockDriver bdrv_replication = {
+ * .format_name = "replication",
+ * .protocol_name = "replication",
+ * .instance_size = sizeof(BDRVReplicationState),
+ *
+ * .bdrv_open = replication_open,
+ * .bdrv_close = replication_close,
+ * };
+ *
+ * static void bdrv_replication_init(void)
+ * {
+ * bdrv_register(&bdrv_replication);
+ * }
+ *
+ * block_init(bdrv_replication_init);
+ * </programlisting>
+ * </example>
+ *
+ * We create an example about how to use replication interface in above.
+ * Then in migration, we can use replication_(start/stop/do_checkpoint/
+ * get_error)_all to handle all replication operations.
+ */
+
+/**
+ * ReplicationState:
+ * @opaque: opaque pointer value passed to this ReplicationState
+ * @ops: replication operation of this ReplicationState
+ * @node: node that we will insert into @replication_states QLIST
+ */
+struct ReplicationState {
+ void *opaque;
+ ReplicationOps *ops;
+ QLIST_ENTRY(ReplicationState) node;
+};
+
+/**
+ * ReplicationOps:
+ * @start: callback to start replication
+ * @stop: callback to stop replication
+ * @checkpoint: callback to do checkpoint
+ * @get_error: callback to check if error happened in replication
+ */
+struct ReplicationOps{
+ void (*start)(ReplicationState *rs, ReplicationMode mode, Error **errp);
+ void (*stop)(ReplicationState *rs, bool failover, Error **errp);
+ void (*checkpoint)(ReplicationState *rs, Error **errp);
+ void (*get_error)(ReplicationState *rs, Error **errp);
+};
+
+/**
+ * replication_new:
+ * @opaque: opaque pointer value passed to ReplicationState
+ * @ops: replication operation of the new relevant ReplicationState
+ *
+ * Called to create a new ReplicationState instance, and then insert it
+ * into @replication_states QLIST
+ *
+ * Returns: the new ReplicationState instance
+ */
+ReplicationState *replication_new(void *opaque, ReplicationOps *ops);
+
+/**
+ * replication_remove:
+ * @rs: the ReplicationState instance to remove
+ *
+ * Called to remove a ReplicationState instance, and then delete it from
+ * @replication_states QLIST
+ */
+void replication_remove(ReplicationState *rs);
+
+/**
+ * replication_start_all:
+ * @mode: replication mode that could be "primary" or "secondary"
+ * @errp: returns an error if this function fails
+ *
+ * Start replication, called in migration/checkpoint thread
+ *
+ * Note: the caller of the function *MUST* make sure vm stopped
+ */
+void replication_start_all(ReplicationMode mode, Error **errp);
+
+/**
+ * replication_do_checkpoint_all:
+ * @errp: returns an error if this function fails
+ *
+ * This interface is called after all VM state is transferred to Secondary QEMU
+ */
+void replication_do_checkpoint_all(Error **errp);
+
+/**
+ * replication_get_error_all:
+ * @errp: returns an error if this function fails
+ *
+ * This interface is called to check if error happened in replication
+ */
+void replication_get_error_all(Error **errp);
+
+/**
+ * replication_stop_all:
+ * @failover: boolean value that indicates if we need do failover or not
+ * @errp: returns an error if this function fails
+ *
+ * It is called on failover. The vm should be stopped before calling it if you
+ * use this API to shutdown the guest, or other things except failover
+ */
+void replication_stop_all(bool failover, Error **errp);
+
+#endif /* REPLICATION_H */
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [Qemu-devel] [PATCH v16 7/8] Implement new driver for block replication
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
` (5 preceding siblings ...)
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 6/8] Introduce new APIs to do replication operation Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 8/8] support replication driver in blockdev-add Changlong Xie
2016-03-24 6:19 ` [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Wen Congyang
8 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
block/Makefile.objs | 1 +
block/replication.c | 619 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 620 insertions(+)
create mode 100644 block/replication.c
diff --git a/block/Makefile.objs b/block/Makefile.objs
index fa05f37..94c1d03 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -23,6 +23,7 @@ block-obj-$(CONFIG_LIBSSH2) += ssh.o
block-obj-y += accounting.o
block-obj-y += write-threshold.o
block-obj-y += backup.o
+block-obj-y += replication.o
common-obj-y += stream.o
common-obj-y += commit.o
diff --git a/block/replication.c b/block/replication.c
new file mode 100644
index 0000000..eec2e3c
--- /dev/null
+++ b/block/replication.c
@@ -0,0 +1,619 @@
+/*
+ * Replication Block filter
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 Intel Corporation
+ * Copyright (c) 2016 FUJITSU LIMITED
+ *
+ * Author:
+ * Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "block/nbd.h"
+#include "block/blockjob.h"
+#include "block/block_int.h"
+#include "replication.h"
+
+typedef struct BDRVReplicationState {
+ ReplicationMode mode;
+ int replication_state;
+ BdrvChild *active_disk;
+ BdrvChild *hidden_disk;
+ BdrvChild *secondary_disk;
+ char *top_id;
+ ReplicationState *rs;
+ Error *blocker;
+ int orig_hidden_flags;
+ int orig_secondary_flags;
+ int error;
+} BDRVReplicationState;
+
+enum {
+ BLOCK_REPLICATION_NONE, /* block replication is not started */
+ BLOCK_REPLICATION_RUNNING, /* block replication is running */
+ BLOCK_REPLICATION_FAILOVER, /* failover is running in background */
+ BLOCK_REPLICATION_FAILOVER_FAILED, /* failover failed */
+ BLOCK_REPLICATION_DONE, /* block replication is done(after failover) */
+};
+
+static void replication_start(ReplicationState *rs, ReplicationMode mode,
+ Error **errp);
+static void replication_do_checkpoint(ReplicationState *rs, Error **errp);
+static void replication_get_error(ReplicationState *rs, Error **errp);
+static void replication_stop(ReplicationState *rs, bool failover,
+ Error **errp);
+
+#define REPLICATION_MODE "mode"
+#define REPLICATION_TOP_ID "top-id"
+static QemuOptsList replication_runtime_opts = {
+ .name = "replication",
+ .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head),
+ .desc = {
+ {
+ .name = REPLICATION_MODE,
+ .type = QEMU_OPT_STRING,
+ },
+ {
+ .name = REPLICATION_TOP_ID,
+ .type = QEMU_OPT_STRING,
+ },
+ { /* end of list */ }
+ },
+};
+
+static ReplicationOps replication_ops = {
+ .start = replication_start,
+ .checkpoint = replication_do_checkpoint,
+ .get_error = replication_get_error,
+ .stop = replication_stop,
+};
+
+static int replication_open(BlockDriverState *bs, QDict *options,
+ int flags, Error **errp)
+{
+ int ret;
+ BDRVReplicationState *s = bs->opaque;
+ Error *local_err = NULL;
+ QemuOpts *opts = NULL;
+ const char *mode;
+ const char *top_id;
+
+ ret = -EINVAL;
+ opts = qemu_opts_create(&replication_runtime_opts, NULL, 0, &error_abort);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (local_err) {
+ goto fail;
+ }
+
+ mode = qemu_opt_get(opts, REPLICATION_MODE);
+ if (!mode) {
+ error_setg(&local_err, "Missing the option mode");
+ goto fail;
+ }
+
+ if (!strcmp(mode, "primary")) {
+ s->mode = REPLICATION_MODE_PRIMARY;
+ } else if (!strcmp(mode, "secondary")) {
+ s->mode = REPLICATION_MODE_SECONDARY;
+ top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
+ if (!(s->top_id = g_strdup(top_id))) {
+ error_setg(&local_err, "Missing the option top-id");
+ goto fail;
+ }
+ } else {
+ error_setg(&local_err,
+ "The option mode's value should be primary or secondary");
+ goto fail;
+ }
+
+ s->rs = replication_new(bs, &replication_ops);
+
+ ret = 0;
+
+fail:
+ qemu_opts_del(opts);
+ error_propagate(errp, local_err);
+
+ return ret;
+}
+
+static void replication_close(BlockDriverState *bs)
+{
+ BDRVReplicationState *s = bs->opaque;
+
+ if (s->mode == REPLICATION_MODE_SECONDARY) {
+ g_free(s->top_id);
+ }
+
+ if (s->replication_state == BLOCK_REPLICATION_RUNNING) {
+ replication_stop(s->rs, false, NULL);
+ replication_remove(s->rs);
+ }
+}
+
+static int64_t replication_getlength(BlockDriverState *bs)
+{
+ return bdrv_getlength(bs->file->bs);
+}
+
+static int replication_get_io_status(BDRVReplicationState *s)
+{
+ switch (s->replication_state) {
+ case BLOCK_REPLICATION_NONE:
+ return -EIO;
+ case BLOCK_REPLICATION_RUNNING:
+ return 0;
+ case BLOCK_REPLICATION_FAILOVER:
+ return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0;
+ case BLOCK_REPLICATION_FAILOVER_FAILED:
+ return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 1;
+ case BLOCK_REPLICATION_DONE:
+ /*
+ * active commit job completes, and active disk and secondary_disk
+ * is swapped, so we can operate bs->file directly
+ */
+ return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0;
+ default:
+ abort();
+ }
+}
+
+static int replication_return_value(BDRVReplicationState *s, int ret)
+{
+ if (s->mode == REPLICATION_MODE_SECONDARY) {
+ return ret;
+ }
+
+ if (ret < 0) {
+ s->error = ret;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static coroutine_fn int replication_co_readv(BlockDriverState *bs,
+ int64_t sector_num,
+ int remaining_sectors,
+ QEMUIOVector *qiov)
+{
+ BDRVReplicationState *s = bs->opaque;
+ int ret;
+
+ if (s->mode == REPLICATION_MODE_PRIMARY) {
+ /* We only use it to forward primary write requests */
+ return -EIO;
+ }
+
+ ret = replication_get_io_status(s);
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = bdrv_co_readv(bs->file->bs, sector_num, remaining_sectors, qiov);
+ return replication_return_value(s, ret);
+}
+
+static coroutine_fn int replication_co_writev(BlockDriverState *bs,
+ int64_t sector_num,
+ int remaining_sectors,
+ QEMUIOVector *qiov)
+{
+ BDRVReplicationState *s = bs->opaque;
+ QEMUIOVector hd_qiov;
+ uint64_t bytes_done = 0;
+ BdrvChild *top = bs->file;
+ BdrvChild *base = s->secondary_disk;
+ BlockDriverState *target;
+ int ret, n;
+
+ ret = replication_get_io_status(s);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (ret == 0) {
+ ret = bdrv_co_writev(top->bs, sector_num,
+ remaining_sectors, qiov);
+ return replication_return_value(s, ret);
+ }
+
+ /*
+ * Failover failed, only write to active disk if the sectors
+ * have already been allocated in active disk/hidden disk.
+ */
+ qemu_iovec_init(&hd_qiov, qiov->niov);
+ while (remaining_sectors > 0) {
+ ret = bdrv_is_allocated_above(top->bs, base->bs, sector_num,
+ remaining_sectors, &n);
+ if (ret < 0) {
+ return ret;
+ }
+
+ qemu_iovec_reset(&hd_qiov);
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done, n * BDRV_SECTOR_SIZE);
+
+ target = ret ? (top->bs) : (base->bs);
+ ret = bdrv_co_writev(target, sector_num, n, &hd_qiov);
+ if (ret < 0) {
+ return ret;
+ }
+
+ remaining_sectors -= n;
+ sector_num += n;
+ bytes_done += n * BDRV_SECTOR_SIZE;
+ }
+
+ return 0;
+}
+
+static bool replication_recurse_is_first_non_filter(BlockDriverState *bs,
+ BlockDriverState *candidate)
+{
+ return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
+}
+
+static void secondary_do_checkpoint(BDRVReplicationState *s, Error **errp)
+{
+ Error *local_err = NULL;
+ int ret;
+
+ if (!s->secondary_disk->bs->job) {
+ error_setg(errp, "Backup job was cancelled unexpectedly");
+ return;
+ }
+
+ backup_do_checkpoint(s->secondary_disk->bs->job, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ ret = s->active_disk->bs->drv->bdrv_make_empty(s->active_disk->bs);
+ if (ret < 0) {
+ error_setg(errp, "Cannot make active disk empty");
+ return;
+ }
+
+ ret = s->hidden_disk->bs->drv->bdrv_make_empty(s->hidden_disk->bs);
+ if (ret < 0) {
+ error_setg(errp, "Cannot make hidden disk empty");
+ return;
+ }
+}
+
+static void reopen_backing_file(BDRVReplicationState *s, bool writable,
+ Error **errp)
+{
+ BlockReopenQueue *reopen_queue = NULL;
+ int orig_hidden_flags, orig_secondary_flags;
+ int new_hidden_flags, new_secondary_flags;
+ Error *local_err = NULL;
+
+ if (writable) {
+ orig_hidden_flags = s->orig_hidden_flags =
+ bdrv_get_flags(s->hidden_disk->bs);
+ new_hidden_flags = (orig_hidden_flags | BDRV_O_RDWR) &
+ ~BDRV_O_INACTIVE;
+ orig_secondary_flags = s->orig_secondary_flags =
+ bdrv_get_flags(s->secondary_disk->bs);
+ new_secondary_flags = (orig_secondary_flags | BDRV_O_RDWR) &
+ ~BDRV_O_INACTIVE;
+ } else {
+ orig_hidden_flags = (s->orig_hidden_flags | BDRV_O_RDWR) &
+ ~BDRV_O_INACTIVE;
+ new_hidden_flags = s->orig_hidden_flags;
+ orig_secondary_flags = (s->orig_secondary_flags | BDRV_O_RDWR) &
+ ~BDRV_O_INACTIVE;
+ new_secondary_flags = s->orig_secondary_flags;
+ }
+
+ if (orig_hidden_flags != new_hidden_flags) {
+ reopen_queue = bdrv_reopen_queue(reopen_queue, s->hidden_disk->bs, NULL,
+ new_hidden_flags);
+ }
+
+ if (!(orig_secondary_flags & BDRV_O_RDWR)) {
+ reopen_queue = bdrv_reopen_queue(reopen_queue, s->secondary_disk->bs, NULL,
+ new_secondary_flags);
+ }
+
+ if (reopen_queue) {
+ bdrv_reopen_multiple(reopen_queue, &local_err);
+ error_propagate(errp, local_err);
+ }
+}
+
+static void backup_job_cleanup(BDRVReplicationState *s)
+{
+ BlockDriverState *top_bs;
+
+ top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL);
+ if (!top_bs) {
+ return;
+ }
+ bdrv_op_unblock_all(top_bs, s->blocker);
+ error_free(s->blocker);
+ reopen_backing_file(s, false, NULL);
+}
+
+static void backup_job_completed(void *opaque, int ret)
+{
+ BDRVReplicationState *s = opaque;
+
+ if (s->replication_state != BLOCK_REPLICATION_FAILOVER) {
+ /* The backup job is cancelled unexpectedly */
+ s->error = -EIO;
+ }
+
+ backup_job_cleanup(s);
+}
+
+static void replication_start(ReplicationState *rs, ReplicationMode mode,
+ Error **errp)
+{
+ BlockDriverState *bs = rs->opaque;
+ BDRVReplicationState *s;
+ BlockDriverState *top_bs;
+ int64_t active_length, hidden_length, disk_length;
+ AioContext *aio_context;
+ Error *local_err = NULL;
+
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+ s = bs->opaque;
+
+ if (s->replication_state != BLOCK_REPLICATION_NONE) {
+ error_setg(errp, "Block replication is running or done");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ if (s->mode != mode) {
+ error_setg(errp, "The parameter mode's value is invalid, needs %d,"
+ " but got %d", s->mode, mode);
+ aio_context_release(aio_context);
+ return;
+ }
+
+ switch (s->mode) {
+ case REPLICATION_MODE_PRIMARY:
+ break;
+ case REPLICATION_MODE_SECONDARY:
+ s->active_disk = bs->file;
+ if (!s->active_disk || !s->active_disk->bs ||
+ !s->active_disk->bs->backing) {
+ error_setg(errp, "Active disk doesn't have backing file");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ s->hidden_disk = s->active_disk->bs->backing;
+ if (!s->hidden_disk->bs || !s->hidden_disk->bs->backing) {
+ error_setg(errp, "Hidden disk doesn't have backing file");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ s->secondary_disk = s->hidden_disk->bs->backing;
+ if (!s->secondary_disk->bs || !s->secondary_disk->bs->blk) {
+ error_setg(errp, "The secondary disk doesn't have block backend");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ /* verify the length */
+ active_length = bdrv_getlength(s->active_disk->bs);
+ hidden_length = bdrv_getlength(s->hidden_disk->bs);
+ disk_length = bdrv_getlength(s->secondary_disk->bs);
+ if (active_length < 0 || hidden_length < 0 || disk_length < 0 ||
+ active_length != hidden_length || hidden_length != disk_length) {
+ error_setg(errp, "active disk, hidden disk, secondary disk's length"
+ " are not the same");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ if (!s->active_disk->bs->drv->bdrv_make_empty ||
+ !s->hidden_disk->bs->drv->bdrv_make_empty) {
+ error_setg(errp,
+ "active disk or hidden disk doesn't support make_empty");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ /* reopen the backing file in r/w mode */
+ reopen_backing_file(s, true, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ aio_context_release(aio_context);
+ return;
+ }
+
+ /* start backup job now */
+ error_setg(&s->blocker,
+ "block device is in use by internal backup job");
+
+ top_bs = bdrv_lookup_bs(s->top_id, s->top_id, errp);
+ if (!top_bs) {
+ aio_context_release(aio_context);
+ return;
+ }
+ bdrv_op_block_all(top_bs, s->blocker);
+ bdrv_op_unblock(top_bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker);
+
+ /*
+ * Must protect backup target if backup job was stopped/cancelled
+ * unexpectedly
+ */
+ bdrv_ref(s->hidden_disk->bs);
+
+ backup_start(s->secondary_disk->bs, s->hidden_disk->bs, 0,
+ MIRROR_SYNC_MODE_NONE, NULL, BLOCKDEV_ON_ERROR_REPORT,
+ BLOCKDEV_ON_ERROR_REPORT, backup_job_completed,
+ s, NULL, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ backup_job_cleanup(s);
+ bdrv_unref(s->hidden_disk->bs);
+ aio_context_release(aio_context);
+ return;
+ }
+ break;
+ default:
+ aio_context_release(aio_context);
+ abort();
+ }
+
+ s->replication_state = BLOCK_REPLICATION_RUNNING;
+
+ if (s->mode == REPLICATION_MODE_SECONDARY) {
+ secondary_do_checkpoint(s, errp);
+ }
+
+ s->error = 0;
+ aio_context_release(aio_context);
+}
+
+static void replication_do_checkpoint(ReplicationState *rs, Error **errp)
+{
+ BlockDriverState *bs = rs->opaque;
+ BDRVReplicationState *s;
+ AioContext *aio_context;
+
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+ s = bs->opaque;
+
+ if (s->mode == REPLICATION_MODE_SECONDARY) {
+ secondary_do_checkpoint(s, errp);
+ }
+ aio_context_release(aio_context);
+}
+
+static void replication_get_error(ReplicationState *rs, Error **errp)
+{
+ BlockDriverState *bs = rs->opaque;
+ BDRVReplicationState *s;
+ AioContext *aio_context;
+
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+ s = bs->opaque;
+
+ if (s->replication_state != BLOCK_REPLICATION_RUNNING) {
+ error_setg(errp, "Block replication is not running");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ if (s->error) {
+ error_setg(errp, "I/O error occurred");
+ aio_context_release(aio_context);
+ return;
+ }
+ aio_context_release(aio_context);
+}
+
+static void replication_done(void *opaque, int ret)
+{
+ BlockDriverState *bs = opaque;
+ BDRVReplicationState *s = bs->opaque;
+
+ if (ret == 0) {
+ s->replication_state = BLOCK_REPLICATION_DONE;
+
+ /* refresh top bs's filename */
+ bdrv_refresh_filename(bs);
+ s->active_disk = NULL;
+ s->secondary_disk = NULL;
+ s->hidden_disk = NULL;
+ s->error = 0;
+ } else {
+ s->replication_state = BLOCK_REPLICATION_FAILOVER_FAILED;
+ s->error = -EIO;
+ }
+}
+
+static void replication_stop(ReplicationState *rs, bool failover, Error **errp)
+{
+ BlockDriverState *bs = rs->opaque;
+ BDRVReplicationState *s;
+ AioContext *aio_context;
+
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+ s = bs->opaque;
+
+ if (s->replication_state != BLOCK_REPLICATION_RUNNING) {
+ error_setg(errp, "Block replication is not running");
+ aio_context_release(aio_context);
+ return;
+ }
+
+ switch (s->mode) {
+ case REPLICATION_MODE_PRIMARY:
+ s->replication_state = BLOCK_REPLICATION_DONE;
+ s->error = 0;
+ break;
+ case REPLICATION_MODE_SECONDARY:
+ if (!failover) {
+ /*
+ * This BDS will be closed, and the job should be completed
+ * before the BDS is closed, because we will access hidden
+ * disk, secondary disk in backup_job_completed().
+ */
+ if (s->secondary_disk->bs->job) {
+ block_job_cancel_sync(s->secondary_disk->bs->job);
+ }
+ secondary_do_checkpoint(s, errp);
+ s->replication_state = BLOCK_REPLICATION_DONE;
+ aio_context_release(aio_context);
+ return;
+ }
+
+ s->replication_state = BLOCK_REPLICATION_FAILOVER;
+ if (s->secondary_disk->bs->job) {
+ block_job_cancel(s->secondary_disk->bs->job);
+ }
+
+ commit_active_start(s->active_disk->bs, s->secondary_disk->bs, 0,
+ BLOCKDEV_ON_ERROR_REPORT, replication_done,
+ bs, errp, true);
+ break;
+ default:
+ aio_context_release(aio_context);
+ abort();
+ }
+ aio_context_release(aio_context);
+}
+
+BlockDriver bdrv_replication = {
+ .format_name = "replication",
+ .protocol_name = "replication",
+ .instance_size = sizeof(BDRVReplicationState),
+
+ .bdrv_open = replication_open,
+ .bdrv_close = replication_close,
+
+ .bdrv_getlength = replication_getlength,
+ .bdrv_co_readv = replication_co_readv,
+ .bdrv_co_writev = replication_co_writev,
+
+ .is_filter = true,
+ .bdrv_recurse_is_first_non_filter = replication_recurse_is_first_non_filter,
+
+ .has_variable_length = true,
+};
+
+static void bdrv_replication_init(void)
+{
+ bdrv_register(&bdrv_replication);
+}
+
+block_init(bdrv_replication_init);
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [Qemu-devel] [PATCH v16 8/8] support replication driver in blockdev-add
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
` (6 preceding siblings ...)
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 7/8] Implement new driver for block replication Changlong Xie
@ 2016-03-11 10:34 ` Changlong Xie
2016-03-24 6:19 ` [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Wen Congyang
8 siblings, 0 replies; 13+ messages in thread
From: Changlong Xie @ 2016-03-11 10:34 UTC (permalink / raw)
To: qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini, Kevin Wolf,
Stefan Hajnoczi
Cc: Changlong Xie, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei, zhanghailiang
From: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
qapi/block-core.json | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index c580a0f..63abae5 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -247,6 +247,7 @@
# 2.2: 'archipelago' added, 'cow' dropped
# 2.3: 'host_floppy' deprecated
# 2.5: 'host_floppy' dropped
+# 2.6: 'replication' added
#
# @backing_file: #optional the name of the backing file (for copy-on-write)
#
@@ -1633,6 +1634,7 @@
# Drivers that are supported in block device operations.
#
# @host_device, @host_cdrom: Since 2.1
+# @replication: Since 2.6
#
# Since: 2.0
##
@@ -1640,8 +1642,8 @@
'data': [ 'archipelago', 'blkdebug', 'blkverify', 'bochs', 'cloop',
'dmg', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
'http', 'https', 'null-aio', 'null-co', 'parallels',
- 'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'tftp', 'vdi', 'vhdx',
- 'vmdk', 'vpc', 'vvfat' ] }
+ 'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'replication',
+ 'tftp', 'vdi', 'vhdx', 'vmdk', 'vpc', 'vvfat' ] }
##
# @BlockdevOptionsBase
@@ -2081,6 +2083,19 @@
{ 'enum' : 'ReplicationMode', 'data' : [ 'primary', 'secondary' ] }
##
+# @BlockdevOptionsReplication
+#
+# Driver specific block device options for replication
+#
+# @mode: the replication mode
+#
+# Since: 2.6
+##
+{ 'struct': 'BlockdevOptionsReplication',
+ 'base': 'BlockdevOptionsGenericFormat',
+ 'data': { 'mode': 'ReplicationMode' } }
+
+##
# @BlockdevOptions
#
# Options for creating a block device.
@@ -2117,6 +2132,7 @@
'quorum': 'BlockdevOptionsQuorum',
'raw': 'BlockdevOptionsGenericFormat',
# TODO rbd: Wait for structured options
+ 'replication':'BlockdevOptionsReplication',
# TODO sheepdog: Wait for structured options
# TODO ssh: Should take InetSocketAddress for 'host'?
'tftp': 'BlockdevOptionsFile',
--
1.9.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints
2016-03-11 10:34 [Qemu-devel] [PATCH v16 0/8] Block replication for continuous checkpoints Changlong Xie
` (7 preceding siblings ...)
2016-03-11 10:34 ` [Qemu-devel] [PATCH v16 8/8] support replication driver in blockdev-add Changlong Xie
@ 2016-03-24 6:19 ` Wen Congyang
8 siblings, 0 replies; 13+ messages in thread
From: Wen Congyang @ 2016-03-24 6:19 UTC (permalink / raw)
To: Changlong Xie, qemu devel, Fam Zheng, Max Reitz, Paolo Bonzini,
Kevin Wolf, Stefan Hajnoczi
Cc: zhanghailiang, qemu block, Jiang Yunhong, Dong Eddie,
Dr. David Alan Gilbert, Michael R. Hines, Gonglei
Ping....
On 03/11/2016 06:34 PM, Changlong Xie wrote:
> Block replication is a very important feature which is used for
> continuous checkpoints(for example: COLO).
>
> You can get the detailed information about block replication from here:
> http://wiki.qemu.org/Features/BlockReplication
>
> Usage:
> Please refer to docs/block-replication.txt
>
> This patch series is based on the following patch series:
> 1. http://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg02319.html
>
> Patch status:
> 1. Acked patches: none
> 2. Reviewed patches: patch 4
> 3. Updated patches: patch 7, 8
>
> You can get the patch here:
> https://github.com/Pating/qemu/tree/changlox/block-replication-v16
>
> You can get the patch with framework here:
> https://github.com/Pating/qemu/tree/changlox/colo_framework_v15
>
> TODO:
> 1. Continuous block replication. It will be started after basic functions
> are accepted.
>
> Changs Log:
> V16:
> 1. Rebase to the newest codes
> 2. Address comments from Stefan & hailiang
> p3: we don't need this patch now
> p4: add "top-id" parameters for secondary
> p6: fix NULL pointer in replication callbacks, remove unnecessary typedefs,
> add doc comments that explain the semantics of Replication
> p7: Refactor AioContext for thread-safe, remove unnecessary get_top_bs()
> *Note*: I'm working on replication testcase now, will send out in V17
> V15:
> 1. Rebase to the newest codes
> 2. Fix typos and coding style addresed Eric's comments
> 3. Address Stefan's comments
> 1) Make backup_do_checkpoint public, drop the changes on BlockJobDriver
> 2) Update the message and description for [PATCH 4/9]
> 3) Make replication_(start/stop/do_checkpoint)_all as global interfaces
> 4) Introduce AioContext lock to protect start/stop/do_checkpoint callbacks
> 5) Use BdrvChild instead of holding on to BlockDriverState * pointers
> 4. Clear BDRV_O_INACTIVE for hidden disk's open_flags since commit 09e0c771
> 5. Introduce replication_get_error_all to check replication status
> 6. Remove useless discard interface
> V14:
> 1. Implement auto complete active commit
> 2. Implement active commit block job for replication.c
> 3. Address the comments from Stefan, add replication-specific API and data
> structure, also remove old block layer APIs
> V13:
> 1. Rebase to the newest codes
> 2. Remove redundant marcos and semicolon in replication.c
> 3. Fix typos in block-replication.txt
> V12:
> 1. Rebase to the newest codes
> 2. Use backing reference to replcace 'allow-write-backing-file'
> V11:
> 1. Reopen the backing file when starting blcok replication if it is not
> opened in R/W mode
> 2. Unblock BLOCK_OP_TYPE_BACKUP_SOURCE and BLOCK_OP_TYPE_BACKUP_TARGET
> when opening backing file
> 3. Block the top BDS so there is only one block job for the top BDS and
> its backing chain.
> V10:
> 1. Use blockdev-remove-medium and blockdev-insert-medium to replace backing
> reference.
> 2. Address the comments from Eric Blake
> V9:
> 1. Update the error messages
> 2. Rebase to the newest qemu
> 3. Split child add/delete support. These patches are sent in another patchset.
> V8:
> 1. Address Alberto Garcia's comments
> V7:
> 1. Implement adding/removing quorum child. Remove the option non-connect.
> 2. Simplify the backing refrence option according to Stefan Hajnoczi's suggestion
> V6:
> 1. Rebase to the newest qemu.
> V5:
> 1. Address the comments from Gong Lei
> 2. Speed the failover up. The secondary vm can take over very quickly even
> if there are too many I/O requests.
> V4:
> 1. Introduce a new driver replication to avoid touch nbd and qcow2.
> V3:
> 1: use error_setg() instead of error_set()
> 2. Add a new block job API
> 3. Active disk, hidden disk and nbd target uses the same AioContext
> 4. Add a testcase to test new hbitmap API
> V2:
> 1. Redesign the secondary qemu(use image-fleecing)
> 2. Use Error objects to return error message
> 3. Address the comments from Max Reitz and Eric Blake
>
> Changlong Xie (1):
> Introduce new APIs to do replication operation
>
> Wen Congyang (7):
> unblock backup operations in backing file
> Backup: clear all bitmap when doing block checkpoint
> Link backup into block core
> docs: block replication's description
> auto complete active commit
> Implement new driver for block replication
> support replication driver in blockdev-add
>
> Makefile.objs | 1 +
> block.c | 18 ++
> block/Makefile.objs | 3 +-
> block/backup.c | 15 ++
> block/mirror.c | 13 +-
> block/replication.c | 619 +++++++++++++++++++++++++++++++++++++++++++++
> blockdev.c | 2 +-
> docs/block-replication.txt | 238 +++++++++++++++++
> include/block/block_int.h | 5 +-
> qapi/block-core.json | 33 ++-
> qemu-img.c | 2 +-
> replication.c | 94 +++++++
> replication.h | 175 +++++++++++++
> 13 files changed, 1208 insertions(+), 10 deletions(-)
> create mode 100644 block/replication.c
> create mode 100644 docs/block-replication.txt
> create mode 100644 replication.c
> create mode 100644 replication.h
>
^ permalink raw reply [flat|nested] 13+ messages in thread